Safe quick-release lock of cartridge feed unit to magazine of firearm

ABSTRACT

Spring-plunger on knob end of cartridge feed unit is seated against forward magazine end to lock feed unit against unintentional release from its pin and bayonet-slot connection with magazine when handling firearm with magazine empty.

United States Patent 11 1 Norman et a1.

SAFE QUICK-RELEASE LOCK OF CARTRIDGE FEED UNIT TO MAGAZINE OF FIREARM Inventors: Gerald F. Norman, Wallingford;

Assignee:

Filed:

William E. Osborne, Guilford, both of Conn.

The Marlin Firearms Company, North Haven, Conn.

Feb. 20, 1974 Appl. No.1 443,942

US. Cl 42/49 R; 42/17; 42/49 Int. Cl. F4lc 25/08 Field of Search 42/49 R, 17, 21

References Cited UNITED STATES PATENTS Stevenson et al 42/17 51 May 20, 1975 951,657 3/1910 Pedersen 42/49 R 993,817 5/1911 Bennett 42/49 R 2,596,841 5/1952 Davidson 42/17 2,785,492 3/1957 Smith 42/17 3,018,577 1/1962 Le Violette, Jr 42/49 R Primary Examiner-Samuel Feinberg Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-Walter Spruegel [5 7] ABSTRACT Spring-plunger on knob end of cartridge feed unit is seated against forward magazine end to lock feed unit against unintentional release from its pin and bayonetslot connection with magazine when handling firearm with magazine empty.

8 Claims, 6 Drawing Figures SAFE QUICK-RELEASE LOCK OF CARTRIDGE FEED UNIT TO MAGAZINE OF FIREARM This invention relates to firearms in general, and to tubular cartridge magazines for firearms in particular.

The invention is concerned with a tubular magazine especially, though not exclusively, of the type having a side slot through which to charge the magazine with cartridges. Accordingly, the cartridge feed parts, in the usual form of a cartridge follower, magazine cap and interposed feed spring, are combined into a unit which as such is retractible from the magazine in order to charge the latter with cartridges through the side slot or, if desired, through the forward end of the magazine. To this end, the cap part of the feed unit is releasably locked to the forward end of the magazine so that on its release therefrom the feed unit may be retracted for reloading the magazine with cartridges in an orderly row therein. In then thrusting the feed unit all the way back into the loaded magazineand relocking it thereto, the spring part of the feed unit is compressed for opera tional function of the latter to urge the row of cartridges rearwardly in the magazine and against the cartridge lifter in the receiver of the firearm, with the spring part remaining sufficiently compressed to urge the last remaining cartridge in the magazine against the cartridge lifter for reliable elevation by the latter in its accustomed transfer to the firing chamber. However, in order to avoid in the empty magazine excessive rearward expansion of the compressed spring part at which the cartridge follower part of the feed unit would reach and jam the action of the cartridge lifter, there is usually provided in the magazine or receiver a safety stop against which the cartridge follower part comes to rest while still out of reach of the cartridge lifter.

A much preferred cartridge feed unit is of a type re sembling a rigid stick in general appearance, feel and handling, by including as its most conspicuous part a hollow tube which carries the cap part of the unit a one end and receives in its interior the cartridge follower and spring parts of the unit, with the follower part being slidable in this tube part and the latter being, in turn, slidable in the tubular magazine and also provided with the aforementioned safety stop. Of course, while the compression of the spring part will, at any loaded stage of the magazine, react with and reenforce the releasable lock, no matter what type, of the feed unit to the magazine, the compression of this spring part will in no way react with the lock of the feed unit to the magazine when the latter is empty, since in that case the spring compression, besides remaining exerted against the cap part, is now exerted also against the safety stop through intermediation of the cartridge follower part which then rests against this stop, wherefore the compressive force of the spring'is now wholly dissipated within the feed unit. It is for this reason that for cartridge feed units of this type the releasable lock of the cap part to the magazine must be designed to function safely and without reliance on the spring part of these units in any condition of the magazine, loaded or empty. Among known releasible locks designed to that end are threaded connections between the cap parts of the feed units and the forward ends of the associated magazines, and also connections of quick twist type. However, threaded connections between the usually rather thinwalled cap parts and magazines entail rather costly operations on these parts and, moreover. require more time and patience for their connection and disconnection than is compatible with desirable or imperative quick-loading of magazines, while the twisttype connections are so complex that their cost becomes prohibitive for efficient and low-cost mass production of cartridge feed units.

It is the primary object of the present invention to provide for a tubular magazine a cartridge feed unit of the aforementioned type, of which the releasable connection between the cap part of the unit and the magazine part is of twist type, and features a pin and bayonet-slot connection between these parts, and a lock which not only is responsive solely to the only possible and accustomed manipulation of the cap part for its pin and slot connection with and disconnection from the magazine part to interlock the connected parts and re lease them fordisconnection, respectively, but is also structually so exceedingly simple that its cost is but an insignificant part of the overall cost of the feed unit, and its formation lends itself, equally as well as the formation of the pin and bayonet-slot connection, to mass production of the feed unit at particularly high efficiency. Thus, the featured pin and bayonet-slot connection between the parts, besides being of the utmost structural simplicity and entailing correspondingly low cost as already mentioned, is still further advantageous in that the parts are connected and disconnected not only instantaneously, but also by their characteristically simple manipulation for which connections of this type are noted, while the also featured lock alone warrants the adaptation of, and reliance on, the pin and bayonet-slot connection between the cap and magazine parts for operational lock and release of the latter which is so vital for reliable and safe operation of firearms.

lt is another object of the present invention to provide for a tubular magazine a cartridge feed unit of this type, of which the aforementioned lock for the pin and bayonet-slot connection between the cap part of the feed unit and the magazine part is in the form of a simple spring, and preferably a spring-urged plunger, on the cap part, with this plunger being arranged to first seat on the forward end of the magazine part and then become increasingly spring-loaded on the inward thrust of the cap part in the magazine part for passage of the pin on one of these parts into the axial lead-in branch of the bayonet slot in the other part, so that on subsequently twisting the cap part for register of the pin with the lateral lock branch of the slot the spring-loaded plunger will hold the pin and lateral slot branch in firm engagement, and even in firm interlock if the lateral slot branch has a preferred lock depression. With this arrangement, the spring load on the plunger may also be relatively small and still be tough-perceptible as desired, in order safely to lock the feed unit to the empty magazine against release therefrom and, hence, possible loss of the feed unit in ordinary, and even careless, handling of the firearm, wherefore the plunger and its spring may also readily be kept within dimensions to blend smoothly and least conspicuously with magazines of any dimensions.

Further objects and advantages will appear to those skilled in the art from the following, considered in conjunction with the accompanying drawings.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

FIG. 1 is a fragmentary side view of a firearm with a cartridge magazine and feed embodying the present invention;

FIG. 1A is a fragmentary view of the firearm as seen in the direction of the arrow 1A in FIG. 1,

FIG. 2 is an enlarged fragmentary section through the featured cartridge magazine and feed of the firearm;

FIG. 3 is a fragmentary section similar to FIG. 2, but showing the magazine empty;

FIG. 4 is a fragmentary section similar to a part of FIG. 3, but showing certain prominent parts in a different position; and

FIG. 5 is a fragmentary section through a cartridge magazine and feed which embodies the invention in a modified manner.

Referring to the drawings, and more particularly to FIG. 1 thereof, the reference numeral designates a firearm, in this instance a lever-action rifle, having among its major components a receiver 12, a barrel l4 and a cartridge magazine 16 with a cartridge feed unit 18.

The magazine 16 is of tubular type, with the magazine tube being open at its front and rear ends, and being suitably mounted with its rear end in the receiver 12 and near its front end in a depending lug 13 on the barrel 14 (FIGS. 2 and 3). While the magazine could be loaded with cartridges 0 through its open front end 22, it is preferably loaded through a side slot 24 in the magazine (FIG. 1A). The loaded magazine holds an orderly row of cartridges 0, and the feed unit 18 urges the cartridges one by one into the receiver as needed for firing.

The cartridge feed unit 18 is in this instance in the characteristic form of a rigid stick by having as its most prominent part on elongated tube 26 which carries the remaining parts of the unit in the form of an end cap 28, a cartridge follower and a compression-type feed spring 32 (FIGS. 2 and 3). The cap 28 is mounted at one end of the tube 26, the follower 30 is slidable, and in this instance also turnable, in the tube 26, and the feed spring 32 is confined in this tube and interposed between the end cap 28 and follower 30, with the feed spring 32 being pre-compressed or loaded so as to urge the follower 30 against a rear stop 34 in the tube 26 when the magazine 16 is empty (FIG. 3). The rear stop 34 is in the preferred form of a collar formation on the tube 26 obtained by simple inward crimping of the tube wall thereat.

For operation of the cartridge feed unit 18, the latter is held in the magazine 16 by a connection 36 between the cap 28 and the magazine. However, this connection 36 must be releasable for retraction of the feed unit 18 in, or even from, the magazine 16 to permit loading of the latter through the side slot 24 therein or, if desired, through the forward magazine end 22. In this instance, the feed unit 18, and more particularly its tube 26, is of approximately the same length as the magazine 16, wherefore after loading the latter and reapplying the feed unit thereto, the row of cartridges is confined in the tube 26 (FIG. 2). In operation of the feed unit 18, the spring-urged follower 30 bears against the foremost cartridge and thereby urges the entire row of cartridges rearwardly to bring the rearmost cartridge in the row into transfer engagement with the customary cartridge lifter 38 in the receiver for elevation of the cartridge and its continuing transfer in usual manner into the firing chamber by the closing breech block (neither shown). Involved in this instance in the transfer of a cartridge into the firing chamber is a feed throat 40 which in known manner assists in guiding the cartridge into the firing chamber. The springurged follower 30 thus transfers successive cartridges of the row to the cartridge lifter as needed for repeated firing of the firearm and until the magazine is empty. When the magazine is empty, the cartridge follower 30 is against the rear or safety stop 34 in the tube 26 and is thereby held out ofjamming reach of the cartridge lifter 38 (FIG. 3).

The releasable connection 36 between the magazine 16 and the cap 28 of the cartridge feed unit 18 is of featured pin and bayonet-slot type, with the pin 42 being in this instance carried by the cap 28, and the bayonet slot 44 being provided in the forward end of the magazine. The bayonet slot 44 has the'usual axis lead-in branch 46 and continuing lateral lock branch 48. The pin 42 of the connection 36 serves in this instance also for securely mounting the cap 28 on the tube 26 of the feed unit 18, by preferred press-fitted reception of the pin 42 in aligned holes 50 and 52 in the tube 26 and in a reduced rear shank 54 of the cap 28, respectively, with the shank 54 extending into, and thereby closing, the open forward end of the tube 26 (FIG. 3). The cap 28 is in this instance also provided with a round and preferably knurled knob formation 56 which is accessible at the forward end of the magazine for manipulation of the feed unit 18 in connecting the same with, and releasing it from, the magazine at the featured pin and bayonet-slot connection 36. Thus, with the magazine l6 empty as in FIG. 3 and in order to reload the same with cartridges, the feed unit 18 is retracted in or from the magazine by maninpulation of the knob 56, first in twist fashion to move the pin 42 out of the lateral lock branch 48 and into the axial branch 46 of the bayonet slot 44 in the magazine, and then in straight pull fashion to retract the pin 42 from the slot branch 46, as will be readily understood. After then reloading the magazine with cartridges, the feed unit 18 is reapplied to the magazine by thrusting it back into the latter, with the knob 56 being then manipulated, after first bringing the pin 42 into alignment with the lead-in branch 46 of the bayonet slot, in successive straight thrust and twist fashion to pass the pin 42 into the leadin branch 46 and continuing lock branch 48 of the slot for connection of the feed unit with the magazine (FIGS. 2 and 3).

The featured pin and bayonet-slot connection between the feed unit and magazine is highly advantageous because the same lends itself not only to mass production of magazines and associated feed units at particularly high efficiency and low cost, but also to connection of the feed unit with, and its release from, the magazine with the ease and virtually instantaneous rapidity for which connections of pin and bayonet-slot type are noted.

While the magazine 16 holds any number of cartridges, including one last cartridge, the preloaded feed spring 32, then reacting with the cartridge lifter through intermediation of the follower and remaining cartridge or cartridges, also reacts with the magazine through the therewith connected feed unit, resulting in advantageous forced seating of the pin 42 in the lock branch 48 of the bayonet slot 44, with this pin being then even interlocked with this slot branch if the latter has a preferred depression 60 (FIG. 2). However, once the magazine is empty and the cartridge follower seated in consequence against the safety stop 34 in the tube 26, the pre-compression of the feed spring is transmitted to, and wholly absorbed by the tube 26 and, hence, is without any effect on the pin and bayonet-slot connection 36. Accordingly, it is-entirely possible that, in careless and even careful handling of the firearm with the magazine empty, the feed unit 18 may twist sufficiently in the magazine to move the pin 42 out of register with the lock branch 48 of the bayonet slot 44 and thereby release the feed unit for unintentional retraction in the magazine, if not from the magazine with ensuing possible permanent loss of the feed unit. To avoid such accidental release of the feed unit from the magazine in any event and, hence, possible loss of the feed unit, there is also provided a lock 62 for the pin and bayonet-slot connection 36 between the feed unit and magazine. This lock is in the form of also featured simple spring means, and preferably a plunger 64 with a back-up spring 66, with this spring-backed plunger being carried preferably by the feed unit 18 and reacting with the magazine to function the same as the preloaded feed spring 32 in the loaded magazine, i.e., to hold the pin 42 in forced seating engagement with, and in this instance even in interlock with the depression 60 in, the lock branch 48 of the bayonet slot 44 (FIG. 2). The plunger 64 is ring-shaped and has an inward flange 68 which surrounds a stepped-up extension 70 of the shank 54 of the cap 28, and is seatable against the adjacent shoulder end 72 of the tube 26, and the helical back-up spring 66 surrounds the shank extension 70 and is interposed between the ring plunger 64 and an annular shoulder on the knob end 56 of the cap. The back-up spring 66 is preferably pre-compressed in order normally to hold the ring plunger seated with its flange 68 on the shoulder end 72 of the tube 26 (FIG. 4), with the annular skirt 76 of the plunger then surrounding the tube 26 and also being in alignment with the forward magazine end 22 when the feed unit is inserted in the magazine.

In reapplying the feed unit 18 to the magazine 16 after loading the latter with cartridges, the feed unit is at the knob 56 thrust back into the magazine, with the pin 42 being brought into register with the leadin branch 46 of the bayonet slot 44. In the course of passing the pin 42 into the slot branch 46, the pin will reach the momentary dot-and-dash line position 42' in FIG. 2 in which the ring plunger 64 is still seated against the shoulder end 72 of the tube 26, and is now also seated on the forward magazine end 22 (FIG. 4), so that on continued inward thrust of the feed unit for passage of the pin 42 into alignment with the lock branch 48 of the bayonet slot 44, the ring plunger 64 remains seated on the forward end 22 of the magazine with ensuing increased compression of the precompressed back-up spring 66 (FIG. 3). In then twisting the feed unit at the knob 56 for passing the pin 42 into the lock branch 48 of the bayonet slot and into register with the depression 60 therein, the back-up spring 66 will remain under increased compression, and the whole compressive force of the spring is now exerted on the pin 42 to hold it in firm engagement and interlock with the depression 60 in the slot branch 48. Of course, while the feed unitis applied to the magazine and the latter is loaded with cartridges, and even only one remaining cartridges, the feed spring 32 will add its force to that of the back-up spring 66 in holding the pin 42 in forced interlock with the depression 60 in the slot branch 48. However, and

as already explained, the preloaded feed spring 32 is without any holding effect whatsoever on the pin and bayonet-slot connection 36 between the feed unit and magazine when the latter is empty, but in that event the independently acting spring-backed plunger 64 will lock the feed unit to the magazine with adequate force to avoid unintentional release of the feed unit from the magazine and its possible loss in handling the firearm with an empty magazine.

To protect the plunger and spring parts 64 and 66 of the lock 62 from dirt and other matter, there is preferably provided a cover sleeve which extends over the parts 64 and 66, and preferably also over the forward end of the magazine when the feed unit is applied (FIG. 3). The cover sleeve 80 has an endflange 82 which by the spring 66 is backed against the knob 56.

While in the preferred form of the releasable connection between the feed unit and magazine of FIGS. 1 to 4 the bayonet slot 44 is provided in the magazine and the associated pin 42 is carried by the feed unit, it is also feasible to provide the bayonet slot in the feed unit and mount the associated pin on the magazine. Thus, FIG. 5 shows a modified arrangement in which the pin 42a is carried by the magazine 16a, and the bayonet slot 44a is provided in the tube part 26a of the feed unit, with the lead-in branch 46a of the bayonet slot extending in this'instance from the lock branch 48a of the slot all the way to the open rear end of the tube 26a.

What is claimed is:

l. A cartridge feed unit for a firearm with a receiver, a cartridge lifter therein, and a tubular front magazine on the receiver with a load opening forward of the latter, comprising a tube slidable in the magazine and having an end cap accessible at the forward magazine end and manipulatable to retract the tube from and thrust it into a home position in which said cap closes the forward magazine end. a cartridge follower slidable in said tube, a compression spring in said tube between said cap and follower and preloaded to urge the latter rearwardly for holding the rearmost of any number of cartridges in the magazine, including one, in transfer engagement with the lifter, a stop in said tube to hold said follower out of jamming reach of the lifter when the magazine is empty, said cap and magazine being termed members, respectively, a releasable connection between said members to hold said tube in said home position, with said connection providing companion pin and bayonet slot formations on the respective members, and said connection being made on said tubethrust manipulation and a succeeding twist manipulation of said cap member, and a lock for said connection providing spring means carried by one of said members, and becoming first seated on the other member and then loaded on said tube-thrust manipulation of said cap member, with said spring means remaining loaded on the succeeding twist manipulation of said cap member.

2. A cartridge feed unit as in claim 1, in which said load opening in the magazine is a side slot therein, and said tube in said home position closing said side slot.

3. A cartridge feed unit as in claim 1, in which said pin and bayonet-slot formations are provided on said cap and in the forward magazine end, respectively.

4. A cartridge feed unit as in claim 3, in which said spring means is carried by said cap.

5. A cartridge feed unit as in claim 4, in which said spring means is a spring-backed ring plunger which becomes seated against the forward magazine end on said tube-thrust manipulation of said cap.

6. A cartridge feed unit as in claim 5, in which said tube has a first shoulder, and said ring plunger is in retracted condition of said tube held seated against said shoulder by the backing spring, whereby the latter is kept preloaded.

7. A cartridge feed unit as in claim 6, in which said cap has a round knob and a diametrically reduced shank with an annular shoulder between them. of which said shank has an exposed length leading from said annular shoulder and a continuing endlength reposition of said tube. 

1. A cartridge feed unit for a firearm with a receiver, a cartridge lifter therein, and a tubular front magazine on the receiver with a load opening forward of the latter, comprising a tube slidable in the magazine and having an end cap accessible at the forward magazine end and manipulatable to retract the tube from and thrust it into a home position in which said cap closes the forward magazine end, a cartridge follower slidable in said tube, a compression spring in said tube between said cap and follower and preloaded to urge the latter rearwardly for holding the rearmost of any number of cartridges in the magazine, including one, in transfer engagement with the lifter, a stop in said tube to hold said follower out of jamming reach of the lifter when the magazine is empty, said cap and magazine being termed members, respectively, a releasable connection between said members to hold said tube in said home position, with said connection providing companion pin and bayonet slot formations on the respective members, and said connection being made on said tubethrust manipulation and a succeeding twist manipulation of said cap member, and a lock for said connection providing spring means carried by one of said members, and becoming first seated on the other member and then loaded on said tube-thrust manipulation of said cap member, with said spring means remaining loaded on the succeeding twist manipulation of said cap member.
 2. A cartridge feed unit as in claim 1, in which said load opening in the magazine is a side slot therein, and said tube in said home position closing said side slot.
 3. A cartridge feed unit as in claim 1, in which said pin and bayonet-slot formations are provided on said cap and in the forward magazine end, respectively.
 4. A cartridge feed unit as in claim 3, in which said spring means is carried by said cap.
 5. A cartridge feed unit as in claim 4, in which said spring means is a spring-backed ring plunger which becomes seated against the forward magazine end on said tube-thrust manipulation of said cap.
 6. A cartridge feed unit as in claim 5, in which said tube has a first shoulder, and said ring plunger is in retracted condition of said tube held seated against said shoulder by the backing spring, whereby the latter is kept preloaded.
 7. A cartridge feed unit as in claim 6, in which said cap has a round knob and a diametrically reduced shank with an annular shoulder between them, of which said shank has an exposed length leading from said annular shoulder and a continuing endlength received in and secured to said tube, said first shoulder being the forward end of said tube, and said ring plunger and backing spring surrounding said exposed shank length, with the backing spring being of helical type and interposed between said annular shoulder and ring plunger.
 8. A cartridge feed unit as in claim 7, in which there is further provided a cover sleeve extending rearwardly from said knob over said plunger and backing spring, and also over the forward magazine end in said home position of said tube. 